1. Field of the Invention
This invention relates to an electronic clapper board and a method of using the electronic clapper board for synchronizing film.
2. Description of the Prior Art
Since the advent of film with soundtrack, or xe2x80x9cTalkiesxe2x80x9d, film makers had to devise methods of combining sound recorded on the set with the corresponding film footage, because while the picture was recorded onto film within a camera, sound was recorded onto tape on it""s own separate apparatus with it""s own power and controls and operated totally independent of the camera.
The simplest technique of combining the picture and the sound is the use of the Clapper Board or Slate. A person holds the clapper board in front of the camera, shouts out the scene, slate and take number, and then claps the slate shut.
The clapping sound is useful in matching a specific visual event to a specific auditory event. An editor looks at the film one frame at a time to locate the exact frame when the clapper board shut. The editor then listens to the sound one frame at a time to find the exact frame when the corresponding xe2x80x9cclap soundxe2x80x9d begins. The exact frame when the clapper board shut and the xe2x80x9cclap soundxe2x80x9d begins is called the Sync Frame.
Until the advent of video recording, sound to film synchronization was performed by mechanical means. This mainly relied on sprockets in the film and in special sprocketed recording tape. Relative timing adjustments could be made by slipping sprocket holes, so when video arrived an electronic equivalent was needed to take the place of mechanical methods and synchronization.
In 1967, the US Society of Motion Pictures and Television Engineers introduced SMPTE timecode. SMPTE timecode is an 80 bit binary code. The original uses of SMPTE timecode include accurate video editing and synchronizing film soundtracks. The timing data in SMPTE takes the form of an eight digit twenty-four hour clock. The count consists of 0 to 59 seconds, 0 to 59 minutes, and 0 to 23 hours. The second is subdivided into a number of frames. The frame-rate is the number of times a second that the picture is updated so as to give the illusion of continuous movement. In North America, the frame-rate is 30 frames per second, but Europe uses a 25 frame per second timecode called EBU timecode.
The film industry generally uses a special clapper, commonly known as a Smart Slate, (U.S. Pat. No. 4,646,167) which has a running numeric display showing the timecode position of the audio recorders timecode. After the film is processed in a laboratory, it is transferred to videotape using a Telecine or scanner. This transfer is known as a xe2x80x9cfilm to tapexe2x80x9d transfer. During this transfer the editor goes through a series of steps to synchronize the picture and sound:
(a) the editor stops the film on the sync frame (the frame where the clapper closes) for a take;
(b) the editor then takes note of the timecode number which is displayed on the slates visual display;
(c) the timecode number is manually entered into a synchronizer;
(d) the synchronizer directs the audio recorder to go to that exact timecode address;
and the film and audio for the first take run in synchronization as they are recorded to videotape.
When the take is finished, the editor stops the videotape from recording and cues the film forward so he can find the exact frame where the dapper closed for take #2 and the process is repeated.
This process takes about four (4) hours and costs over a thousand dollars to synchronize one hour of film. That is, the service currently costs hundreds of dollars per hour performed with an average efficiency ratio of 4:1. If the production takes are less than thirty seconds in length, as in TV commercials, the synchronizing efficiency ratio can increase to 6:1 or 7:1.
Once the sound and picture have been synchronized to videotape, the videotape is then digitized into electronic format where the takes or parts thereof can be combined by a Non-Linear Editing System. These are non-linear due to their ability to manipulate the media in ways far more flexible than the linear counterparts. Instead of having to sequentially fast forward the tape through all the prior takes in order reach a specific take on the tape, a non-linear system permits access of the specific take in a direct fashion, for editing, recording or other purposes.
There is a need for an apparatus and associated method to automate the synchronization of auditory and visual elements.
This invention meets the above need by providing for a clapper board for synchronizing film with audio including: a body; operable sound producing means, attached to the body and adapted to present a simultaneous physical synchronizing video indication and an electrical synchronizing indication of when the said means is operated; a receiver in the body for receiving a plurality of audio timecodes transmitted from an audio recorder; a processor connected to the sound producing means for receiving the electrical synchronizing indication from the sound producing means and to the receiver for receiving the plurality of audio timecodes from the receiver, the processor adapted to send a synchronizing audio timecode associated with the moment when the electrical synchronizing indication is received; and data storage coupled to the processor.
In a variation, operable sound means of the clapper board includes a clapper. In a further variation, the operable sound means includes a display and the synchronizing video indication is a machine readable code presented on a display in the body. The data storage containing the synchronizing time code is read by a code reader.
This invention is also directed to a clapper board for synchronizing film with audio comprising: a body; a display embedded in one side of the body; a marker board embedded in a further side of the body; an alphanumeric keyboard in the body for entering film information for presentation on the display; a clapper hingeably attached to the body and adapted to present a synchronizing video indication by the display and an electrical synchronizing indication by contact with a micro contact in the body when the clapper is operated; a receiver in the body for receiving a plurality of audio timecodes transmitted from an audio recorder; a processor connected to the sound producing means for receiving the electrical indication from the sound producing means and to the receiver for receiving the plurality of audio timecodes from the receiver, the processor adapted to send a synchronizing audio timecode associated with the moment when the electrical indication is received; data storage coupled to the processor for storing the synchronizing audio timecode and the film information; and means for accessing the synchronizing audio timecode and the film information in the data storage.